As the gunsmoke clears from the streets of Paris, in its place a sense of resolve has set in. In a week, the wounded city will host 45,000 people for the long-awaited climate summit. The French government is insisting that the terror will not stop it going ahead, albeit with heightened security and public marches cancelled.

Among those attending, there is a belief that the violence must not hamper the summit's goal – to deliver a long-awaited new global agreement to tackle climate change.

"I think there will be a sense of duty for Paris to be a success," says Environment Minister Greg Hunt, who will attend the first week of the talks.

Sense of duty: Environment Minister Greg Hunt.

"I think there was in any event. But I think that strong sense of duty might even be heightened because people won't want Paris to have a failure on top of a tragedy."

Despite this sentiment, a deal won't come easily. To be successful, world leaders, ministers and negotiators from 196 countries will have to shrug off years of false starts, weak compromises and bitter divisions that have marred the United Nations climate negotiations. The memory of the deeply flawed Copenhagen summit of 2009 – when sky-high expectations yielded far more division than agreement – lingers.

For the first time, the world is trying to craft an agreement that requires all countries to take action and is durable enough to be built on in the decades ahead.

Former prime minister Kevin Rudd at the failed Copenhagen climate summit in 2009.

They must somehow fairly account for the economic differences between the developed and developing worlds – while also delivering billions of dollars in climate funding to help the poorest nations. Yet there is a prevailing sense that Paris will not be Copenhagen Mark II, and that a deal will emerge.

In a speech last week, US President Barack Obama said, yes, there was a lot of work still to do, but declared: "Nevertheless, I'm optimistic that we can get an outcome that we're all proud of, because we understand what's at stake."

At the other end of the spectrum, Kiribati President Anote Tong – whose tiny Pacific nation is one of the most vulnerable to climate change – told Fairfax Media the signs for Paris appeared positive and much better than six years ago.

Kiribati President Anote Tong was in Australia last week ahead of the Paris climate summit to highlight how it is affecting his tiny country. Photo: Jason South

So what's changed? "Climate change is not just an issue that is discussed in environment ministries any more," says Erwin Jackson, from the Climate Institute. "Its now being discussed in treasuries. It is being discussed in defence departments."

Climate change has been mainstreamed, creeping its way further into the thinking of investment markets and the highest corridors of power in the world's largest economies.

Jackson says these external forces are now, maybe for the first time, pushing their way into the bubble of the UN negotiations. Perhaps the biggest shift is that global investment is flowing more and more into clean energy technology. And business is increasingly considering its climate exposure.

The United Nations reported $270 billion was invested globally in renewable energy last year – up from $45 billion a decade before. At the same time, the cost of clean technologies – particularly solar – have fallen quickly, even though they still make up a small proportion of the world's total energy supply.

"In 10 years, the investment community has built the tools they need to consider carbon risk, they have embedded it in decisions. That's got them engaged in the policy process and that's accelerated the technology disruption," says Emma Herd, head of the Investor Group on Climate Change, which represents Australian firms managing $1 trillion in funds.

Herd says since Copenhagen the UN talks have moved from being negotiations for an environmental agreement to being negotiations for an economic deal with environmental outcomes. That sharpens the mind.

Meanwhile, many countries are putting in place stronger domestic policies to address runaway emissions. Most notable is China, the world's largest emitter, which is pursuing a greener model of economic growth and has pledged to stop its emissions rising before 2030. Its plans include a national emissions trading scheme.

The issue has also moved forward in the US. While Republicans are fighting against it, the Obama administration has promoted rules to start phasing out coal power and pledged to cut emissions by a little more than a quarter compared to 2005 levels by 2025.

This domestic action has been reinforced by a series of bilateral climate change agreements between the world's biggest superpowers. The most famous of these has been between China and the US, sometimes described as the G2.

Bill Hare, chief executive of Berlin-based firm Climate Analytics and an advisor to small island states, says the US and China's commitment to getting a deal should not be underestimated. He compares this to Copenhagen, where a distracted Obama and disruptive China leadership contributed to the talks falling in a heap.

This time, the normally bitter debate over the strength of a country's individual emissions targets will be largely set aside. Instead, nations have been allowed to voluntarily nominate their own targets. At the time of writing 167 countries responsible for 93 per cent of the world's emissions had put forward targets as part of what, in typically impenetrable UN language, are known as "intended nationally determined contributions", or INDCs.

Martijn Wilder, global head of environmental markets for consultants Baker & McKenzie, says the contributions offered are significant, and should be considered a baseline for action.

Greg Hunt applauds their emergence: "Countries can negotiate freely because they are not renegotiating their individual targets."

That said, negotiators land in Paris with significant distance still between the parties on several make or break issues. For starters, the current pledges do not add up to a safe, or even safe-ish, future climate.

Assessments suggest that, even if they are all met, global warming would at best still be 2.7 degrees above pre-industrial levels.

That's better than the more than four degrees of warming the world projected by the end of the century under current emissions trajectories, but well short of the globally agreed target of less than two degrees. Two degrees is the threshold scientists say gives the world a shot at avoiding the worst impacts of climate change – for example, the total collapse of ice sheets in Antarctica and Greenland.

If the planet has any chance of meeting that goal, a Paris deal will need to encourage countries to do more over time. But hard penalties for those dragging their feet are not on the table.

Two principles are emerging. The first is that there will be no backsliding – countries can only raise their ambition. The second is that there are regular reviews of targets. While these reviews may not compel a country to lift its goal, nations would have to justify their decisions, exposing them to international peer pressure. Debate remains among countries about how often these reviews should occur.

Hunt says Australia is pushing to have a review in 2020 and then every five years.

"Nobody is saying 'no deal unless two degrees is delivered with the existing pledges'," Hunt says. "But the deal maker – or the deal breaker – is whether or not we agree to come back periodically for reviews that will progressively get us to the two degree target."

The European Union and China have also backed five-year intervals. But the Indian environment secretary Ashok Lavasa last week said that the country was against any mandatory reviews before 2030. Other countries want them to start mid-decade.

Another lingering issue is how to express the long-term ambition. There are a range of suggestions, from "decarbonisation" and a "carbon neutral future" to less ambitious versions.

But, as it often is in life, perhaps the most vexing issue is money, in particular, how will rich countries make good on their promise to help poorer nations cut emissions and adapt to the climate change that has already occurred.

They have already agreed to deliver $100 billion a year by 2020 from public (read: government aid) and private sources. But there is distrust among developing countries over whether this will be delivered, and increased after 2020. They want guarantees built into any agreement.

Hunt says he was concerned about the state of the finance debate before heading to pre-summit talks earlier this month, but felt a recent OECD assessment had somewhat allayed concerns.

That report found $62 billion a year in climate funding was already being transferred, though there's some dispute about the methodology behind that figure.

Erwin Jackson, of the Climate Institute, says funding is still the hardest area of the negotiations to read. He says Australia should be careful in discussing it because it is yet to show how it will increase its own $200 million commitment to help meet the 2020 goal.

While reports had suggested the Turnbull government might announce a boost to climate funding in Paris, Hunt all but ruled this out. Behind the scenes, the government is saying it has little-to-no money for new announcements at the summit.

While officials are now considering cheaper commitments they can take to Paris, Australia is slated to outline some new measures to help rainforest recovery in the Asia-Pacific. It is a cause Hunt has championed. The minister says at the warm up talks he proposed a side deal in which countries could pledge action on rainforests.

Will McGoldrick, from the Nature Conservancy, says new forests measures are welcome, but Australian support should ultimately return to Howard government levels of funding of about $200 million.

Hunt revealed last week Australia will use the Paris platform to declare that it will beat its short-term 2020 target – a 5 per cut below 2000 levels.

He says Australia also had the flexibility to lift its 2030 goal – a 26 to 28 per cent cut below 2005 levels, which is regarded as a weak target in many circles – if reviews under the deal demanded it. That would likely be done with international carbon credits. The government will consider in 2017 whether to buy them.

Australia will have a large team at the fortnight-long meeting. Prime Minister Malcolm Turnbull will join 120 world leaders in attending the first day. Hunt will be there for the first week, and Foreign Affairs Minister Julie Bishop flies in for the second. Behind them is a group of negotiators, led by Australian environment ambassador Peter Woolcott​, who will carry out the nuts and bolts wrangling.

That team now has a negotiating mandate approved by cabinet. It is understood to be flexible and allows Australia to sign up to a strong agreement, including one with lofty language about the long-term ambition of the agreement.

While financing and reviews will be central, there are other moving parts to nail down. Will the agreement include compensation for poor countries to help them clean-up after climate change-driven disasters – known as a loss and damage mechanism?

What monitoring systems will be put in place to ensure countries are keeping their promises?

The legal nature of the agreement is also at play. The US administration is desperate to ensure it does not trigger the need for approval by a Republican-dominated Congress. It means it wants to ensure legally binding targets are not included in the text.

Added up, any deal reached in Paris will be an extraordinary diplomatic balancing act. But the danger is that, in focusing on getting an agreement, countries might abandon the ultimate goal – building a pathway leading to the ultimate stabilisation of global warming at safe levels.

One potential outcome would involve all INDC pledges packaged up under an agreement, but not much more. That's an improvement on the status quo, but not enough to save the planet – nor to send a strong signal to business that a serious shift to a low carbon future is underway.

Herd says investors are constantly looking for big, long-term signals and Paris "is a whopper in terms of telling you where the global economy is going".

Hare says that if there is a weak agreement, no matter what political gloss is put on it, then governments could return home to find industry telling them to stop moving forward because nobody else is.

"That is one of the risks," Hare says. "If the agreement gets too low on ambition, and the signal is too weak, then the momentum that we have seen in the last year or so – particularly away from coal and big fossil fuel investments – would stop."

Amid all this speculation, the Kiribati President last week visited Australia to press his case for a moratorium he wants considered on new coal mine development.

Anote Tong told Fairfax Media his country was already experiencing the reality of climate change. It includes erosion, saltwater inundation of freshwater supplies and dangerous changes in weather patterns that bring more storms to the fragile, ocean atolls he oversees.

Even if emissions were eventually brought to zero, Tong says, his nation would continue to be in deep trouble – hence, the need for adaptation funding for loss and damage. He believes what is happening in Kiribati should instil a sense of urgency across the globe.

"We want to lend our voice to say 'this is happening to us, we don't want to see it happen to anybody else'," he says. "Let's see if we can arrest this as soon as possible."